Modernity tends to view exile as unduly harsh punishment, and many modern states have abandoned its practice. However, in the European Middle Ages, exile was common and often temporary, a concomitant of infighting among the ruling elite, and a natural alternative given their social infrastructure's lack of alternative solutions for maladaptive behavior or for dealing with powerful men who have lost in the struggle for ruling power. Since exile involves the limits of the law, a truer view of exile provides a truer view of foundational legal concepts. The celebrated exile of the eleventh-century Castilian nobleman and conqueror of Valencia, Rodrigo Díaz, aka, El Cid, provides a good case for reconsidering notions of exile in their historical alterity, especially considering that all parties benefitted from his exile. A comparison of roughly contemporaneous legal documents with Rodrigo Díaz' exile in a literary text and a Latin biography provide new insight about his exile, exile in general, and law in medieval Castile. Exile in medieval Castile makes it evident that exile points to that liminal space between competing interpretations, or systems of law.